A miniaturized MIMO antenna

Abstract

The application belongs to the technical field of antennas and relates to a miniaturized MIMO antenna which comprises a rectangular dielectric substrate, four radiation assemblies arranged on the upper surface of the dielectric substrate and four ground plates arranged on the lower surface of the dielectric substrate; the four radiation assemblies are distributed in axial symmetry about any symmetry axis of the dielectric substrate; the four radiation assemblies correspond to the four ground plates one by one, and the radiation assemblies are arranged above the corresponding ground plates so that the radiation assemblies and the corresponding ground plates form an antenna unit; the radiation assembly comprises a radiation patch and a feed branch; the radiation patch is in a crescent structure, and the feed branch is in a symmetric square wave signal structure; one end of the feed branch is connected with the radiation patch, and the other end of the feed branch is connected with the edge of the dielectric substrate to serve as a feed port. The application can realize dual frequency and miniaturization simultaneously.

Description

Technical Field

[0001] This application relates to the field of antenna technology, and in particular to a miniaturized MIMO antenna. Background Technology

[0002] As mobile communication technology evolves towards fifth generation (5G) and beyond fifth generation (B5G), wireless terminal devices are increasingly demanding higher data transmission rates and greater connection reliability.

[0003] Multiple-input multiple-output (MIMO) technology, by configuring multiple antenna elements at both the transmitting and receiving ends, can significantly improve channel capacity and link stability without increasing additional transmit power or spectrum bandwidth, and has become one of the core technologies of modern wireless communication systems.

[0004] In the existing technology, in order to adapt to the differences in spectrum allocation in different regions of the world and the need for multi-mode coexistence, dual-frequency or multi-frequency MIMO antennas covering multiple discrete frequency bands have become a research hotspot.

[0005] However, despite the significant advantages that dual-band MIMO antennas have shown in improving communication performance, they still face a series of key technical challenges in their design and engineering practice.

[0006] On the one hand, dual-band antennas need to maintain good matching characteristics, radiation efficiency, and high isolation simultaneously across two or more discrete frequency bands, which places higher demands on the antenna's resonant mode design and multi-frequency collaborative optimization. The different coupling paths between different frequency bands make it difficult to directly apply traditional single-frequency decoupling methods to dual-band scenarios. An effective decoupling structure in the low-frequency band may introduce new coupling paths in the high-frequency band, and vice versa, thus creating mutually constraining design challenges and exacerbating the complexity of MIMO antenna design.

[0007] On the other hand, as mobile terminals become thinner and smaller, and the space utilization requirements for base station construction continue to increase, the physical size of antenna elements is constantly being compressed. MIMO systems, however, need to integrate multiple antenna elements within a limited space, resulting in extremely limited spacing between them. This contradiction between the compact layout and the complex path makes integrating four or more MIMO antenna elements in space-constrained portable terminals such as smartphones, tablets, and IoT sensors a severe physical space constraint and technical challenge. Summary of the Invention

[0008] Therefore, it is necessary to provide a miniaturized MIMO antenna that can simultaneously achieve dual-band operation and miniaturization, addressing the aforementioned technical problems.

[0009] A miniaturized MIMO antenna includes: a rectangular dielectric substrate, four radiating components disposed on the upper surface of the dielectric substrate, and four ground planes disposed on the lower surface of the dielectric substrate. The four radiating components are axially symmetric about any axis of symmetry of the dielectric substrate; the four radiating components correspond one-to-one with the four ground planes, and the radiating components are located above the corresponding ground planes so that the radiating components and the corresponding ground planes form an antenna unit. The radiating component includes a radiating patch and a power supply stub; the radiating patch has a crescent-shaped structure, and the power supply stub has a symmetrical square wave signal shape structure; one end of the power supply stub is connected to the radiating patch, and the other end is connected to the edge of the dielectric substrate to serve as a power supply port.

[0010] In one embodiment, the radiation patch includes: a first side, a second side, and a third side; The first side and the second side are both arc-shaped structures, and the third side is a straight structure; The radius of the first side is smaller than the radius of the second side, one corresponding end of the first side and the second side coincide, and the other corresponding end is connected by the third side.

[0011] In one embodiment, the central angles corresponding to the first side and the second side are both greater than 150 degrees, and the opening ends of adjacent radiating patches face the corners of the dielectric substrate.

[0012] In one embodiment, the power supply stub includes: a first strip, a second strip, a third strip, and a fourth strip; The first strip has a rectangular structure, with one end perpendicularly connected to the edge of the dielectric substrate and the other end connected to the second strip; The second strip has a U-shaped structure, with one end perpendicularly connected to the first strip and the other end connected to the third strip; The third strip has a U-shaped structure, with one end connected to the second strip and the other end perpendicularly connected to the fourth strip; The fourth strip has a rectangular structure, with one end connected to the third strip and the other end connected to the radiating patch; The first strip and the fourth strip are exactly the same in shape and size, the second strip and the third strip are exactly the same in shape and size, and the second strip and the third strip are centrally symmetrical about the connection point.

[0013] In one embodiment, the axis of symmetry of the length direction of the first strip, the axis of symmetry of the length direction of the fourth strip, the center of the first side, and the center of the second side are collinear. In one embodiment, the floor is a rectangular structure, the length direction of the floor is consistent with the width direction of the dielectric substrate, and a pair of adjacent sides of the floor are collinear with a pair of adjacent sides of the dielectric substrate.

[0014] In one embodiment, the middle of one long side of the floor is recessed towards the short side of the dielectric substrate to form a rectangular groove; The length direction of the rectangular groove is consistent with the width direction of the dielectric substrate, and the length-to-width ratio of the rectangular groove is 2:1.

[0015] In one embodiment, the floor is also provided with parasitic branches; The parasitic branch has a rectangular structure, with one end connected to the short side of the floor and the other end extending towards the axis of symmetry in the length direction of the dielectric substrate, forming a gap between it and the axis of symmetry in the length direction of the dielectric substrate, so that the parasitic branches of adjacent floorboards are spaced apart.

[0016] In one embodiment, it further includes: a parasitic decoupling strip; The parasitic decoupling strip has a rectangular structure and is located on the lower surface of the dielectric substrate; The length direction of the parasitic decoupling strip is consistent with the length direction of the dielectric substrate, and the parasitic decoupling strip is axially symmetrical about any axis of symmetry of the dielectric substrate.

[0017] In one embodiment, the parasitic decoupling strip has a gap in the middle to divide the parasitic decoupling strip into two identical rectangular branches; The ratio of the length of the rectangular branch, the width of the rectangular branch, and the distance between two rectangular branches is 39:2:15.

[0018] The aforementioned miniaturized MIMO antenna is a dual-band, four-element MIMO antenna. It incorporates a radiating patch, feed stubs, rectangular slots, parasitic stubs, and parasitic decoupling strips (with the rectangular slots and parasitic stubs located on the floor). It achieves four-element integration within a limited space, realizing dual-band wideband coverage in both low and high frequency bands while maintaining high port isolation. It also features dual-band wide coverage, dual-band high isolation, wideband impedance matching, low loss, low profile, miniaturization, thinness, and a simple and compact structure. Furthermore, it exhibits good consistency and radiation characteristics, with stable omnidirectional radiation and excellent diversity performance. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a miniaturized MIMO antenna in one embodiment; Figure 2 This is a top view of a miniaturized MIMO antenna in one embodiment; Figure 3A bottom view of a miniaturized MIMO antenna in one embodiment; Figure 4 A dimensional diagram of a miniaturized MIMO antenna in a specific embodiment; Figure 5 This is an S-parameter curve of a miniaturized MIMO antenna in a specific embodiment; Figure 6 This is a gain curve of a miniaturized MIMO antenna in a specific embodiment; Figure 7 This is an envelope correlation coefficient (ECC) curve of a miniaturized MIMO antenna in a specific embodiment. Figure 8 This is a radiation pattern of a miniaturized MIMO antenna in the E-plane (xoz plane) at 2.45 GHz in a specific embodiment; Figure 9 The radiation pattern of a miniaturized MIMO antenna in the H-plane (yoz plane) at 2.45 GHz is shown in a specific embodiment. Figure 10 The radiation pattern of a miniaturized MIMO antenna in the E-plane (xoz plane) at 5 GHz is shown in a specific embodiment. Figure 11 This is a radiation pattern of a miniaturized MIMO antenna in the H-plane (yoz plane) at 5 GHz in a specific embodiment; Figure 12 The radiation pattern of a miniaturized MIMO antenna in the E-plane (xoz plane) at 5.5 GHz is shown in a specific embodiment. Figure 13 This is a radiation pattern of a miniaturized MIMO antenna in the H-plane (yoz plane) at 5.5 GHz, as shown in a specific embodiment.

[0020] Figure label: Dielectric substrate 1; Radiation patch 2, first side 21, second side 22, third side 23; Power supply branch 3, first strip 31, second strip 32, third strip 33, fourth strip 34; Floor 4, rectangular groove 41, parasitic branch 42; Parasitic decoupling band 5. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0022] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0023] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this application, "multiple sets" means at least two sets, such as two sets, three sets, etc., unless otherwise explicitly specified.

[0024] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] Furthermore, the technical solutions of the various embodiments of this application can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this application.

[0026] This application provides a miniaturized MIMO antenna, such as Figures 1 to 3 As shown, in one embodiment, it includes: a dielectric substrate, four radiating components, and four ground planes. The dielectric substrate has a rectangular structure, providing support space for the radiating components and the floor.

[0027] The radiating components are located on the upper surface of the dielectric substrate and fed through a multi-bend structure. The four radiating components are axially symmetrically distributed about any axis of symmetry of the dielectric substrate. The four radiating components correspond one-to-one with the four ground planes, and the radiating components are located above the corresponding ground planes so that the radiating components and the corresponding ground planes form an antenna element. This effectively utilizes the radiation pattern diversity and polarization diversity characteristics to reduce the envelope correlation coefficient between antenna elements. The radiating components include a radiating patch and a feed stub. The radiating patch has a crescent-shaped structure, and the feed stub has a symmetrical square wave signal shape structure. One end of the feed stub is connected to the radiating patch, and the other end is connected to the edge of the dielectric substrate to serve as a feed port. The port impedance is 50 ohms, which is matched with the SMA interface to facilitate actual testing and system integration.

[0028] The floor is located on the lower surface of the dielectric substrate.

[0029] Preferably, the radiating patch includes a first side, a second side, and a third side; the first and second sides are both arc-shaped structures, and the third side is a straight structure; the radius of the first side is smaller than the radius of the second side, one corresponding end of the first and second sides coincides, and the other corresponding end is connected through the third side. This configuration optimizes impedance matching by utilizing the gradually varying impedance characteristics of arc-shaped edges with different radii; simultaneously, the detour-edge path helps achieve antenna miniaturization, and the structure is simple and easy to manufacture.

[0030] More preferably, the central angles corresponding to the first and second sides are both greater than 150 degrees, and the opening ends of the adjacent radiating patches face the corners of the dielectric substrate, so as to effectively excite high-frequency multi-resonance modes and significantly expand the operating bandwidth.

[0031] More preferably, the feed stub includes: a first strip, a second strip, a third strip, and a fourth strip; the first strip has a rectangular structure, with one end perpendicularly connected to the edge of the dielectric substrate and the other end connected to the second strip; the second strip has a U-shaped structure, with one end perpendicularly connected to the first strip and the other end connected to the third strip; the third strip has a U-shaped structure, with one end connected to the second strip and the other end perpendicularly connected to the fourth strip; the fourth strip has a rectangular structure, with one end connected to the third strip and the other end connected to the radiating patch; the first strip and the fourth strip are identical in shape and size, the second strip and the third strip are identical in shape and size, and the second strip and the third strip are centrally symmetrical about the connection point. This configuration optimizes impedance matching and improves the antenna's S-axis performance. 11 stability.

[0032] More preferably, the axis of symmetry in the length direction of the first strip, the axis of symmetry in the length direction of the fourth strip, the center of the first side, and the center of the second side are collinear, in order to improve S. 11 characteristic.

[0033] In another embodiment, the ground plane is a rectangular structure, with its length direction aligned with the width direction of the dielectric substrate, and a pair of adjacent sides of the ground plane collinear with a pair of adjacent sides of the dielectric substrate. The ground plane is positioned directly below the feed stub of the corresponding radiating component. This configuration effectively stabilizes the characteristic impedance of the feed structure and optimizes the impedance matching characteristics within the dual-band antenna. Simultaneously, the ground plane layout cuts off some ground plane coupling paths between antenna elements, improving port isolation. Furthermore, it contributes to the consistency of the radiation patterns of each antenna element, improving the diversity performance of the MIMO system.

[0034] Preferably, the middle of one long side of the floor is recessed towards the short side of the dielectric substrate to form a rectangular groove; the length direction of the rectangular groove is consistent with the width direction of the dielectric substrate, and the length-to-width ratio of the rectangular groove is 2:1 to improve the isolation.

[0035] More preferably, the floor is also provided with parasitic branches; the parasitic branches are rectangular structures, one end of which is connected to the short side of the floor, and the other end extends toward the axis of symmetry in the length direction of the dielectric substrate, forming a gap with the axis of symmetry in the length direction of the dielectric substrate, so that the parasitic branches of adjacent floor are spaced apart, thereby further improving the isolation.

[0036] More preferably, it further includes: a parasitic decoupling strip; the parasitic decoupling strip has a rectangular structure and is disposed on the lower surface of the dielectric substrate; the length direction of the parasitic decoupling strip is consistent with the length direction of the dielectric substrate, and the parasitic decoupling strip is axially symmetrically distributed about any axis of symmetry of the dielectric substrate. This configuration can effectively suppress electromagnetic coupling between antenna elements without increasing the profile height, significantly improving isolation.

[0037] More preferably, the parasitic decoupling strip has a gap in the middle to divide the parasitic decoupling strip into two identical rectangular branches; the ratio of the length of the rectangular branch, the width of the rectangular branch, and the distance between the two rectangular branches is 39:2:15, so as to further optimize the decoupling effect.

[0038] In this embodiment, the radiating patch, feed branch, ground plane, parasitic branch, and parasitic decoupling strip are all made of metallic materials, while the dielectric substrate is made of non-metallic materials.

[0039] It should be noted that this application can be manufactured using standard printed circuit board processes. The specific processes are existing technologies and will not be described in detail here.

[0040] The aforementioned miniaturized MIMO antenna is a dual-band, four-element MIMO antenna. It incorporates a radiating patch, feed stubs, rectangular slots, parasitic stubs, and parasitic decoupling strips (with the rectangular slots and parasitic stubs located on the floor). It achieves four-element integration within a limited space, realizing dual-band wideband coverage in both low and high frequency bands while maintaining high port isolation. It also features dual-band wide coverage, dual-band high isolation, wideband impedance matching, low loss, low profile, miniaturization, thinness, and a simple and compact structure. Furthermore, it exhibits good consistency and radiation characteristics, with stable omnidirectional radiation and excellent diversity performance.

[0041] Specifically, this application has the following beneficial effects: 1. A crescent-shaped radiating patch and a multi-bend feed stub are incorporated. Through their coordinated design, the antenna excites a resonant frequency in both the high-frequency and low-frequency bands, exhibiting dual-frequency resonance characteristics. This enables dual-band operation (2.40-2.50 GHz and 4.56-6.32 GHz), with the high-frequency bandwidth (4.56-6.32 GHz) fully covering the entire 5GHz WLAN band, 5G Sub-6 GHz n46 / n47 / n96 bands, and part of the C-band satellite communication uplink band (5.85-6.32 GHz). While accommodating terrestrial mobile communications, the antenna also demonstrates application potential in areas such as satellite IoT terminals. Simultaneously, the multi-bend feed stubs form a slow-wave transmission structure within the operating frequency band. Its periodic bends (a symmetrical square wave signal shape structure composed of the first to fourth bands, including two U-shaped sections) introduce distributed series inductance and parallel capacitance, making the phase velocity of the electromagnetic wave in the feed structure significantly lower than the free-space wave velocity. This results in a larger equivalent electrical length for the same physical length within the operating frequency band, achieving excellent impedance matching characteristics. This allows the antenna to achieve low-frequency and high-frequency resonance without increasing the antenna element's projected area and maintaining a compact profile, effectively reducing the antenna size and realizing the miniaturization and integration of dual-frequency MIMO antennas (specifically, at the 2.45 GHz resonant frequency, the projected length of the antenna element on the dielectric substrate is only 23.34 mm, while a quarter wavelength in free space at the same frequency band is approximately 30.6 mm). The antenna element achieves an equivalent quarter-wavelength resonance condition with a projected length of approximately 76%, and the size of this application is reduced by approximately one-quarter compared to the prior art, thus resolving the contradiction between miniaturization and radiation efficiency in the low-frequency band.

[0042] 2. The coordinated design of crescent-shaped radiating patches, multi-bend feed stubs, and parasitic stubs can extend the bandwidth of the antenna.

[0043] 3. Rectangular slots are provided on the floor, which can block the propagation path of some coupled currents on the floor surface, confining the surface current to the local floor area corresponding to each antenna element, thereby improving the isolation.

[0044] 4. Parasitic branches on the floor are set up to introduce additional resonant modes. Excited by the near field of adjacent units, they generate an induced electromagnetic field that is out of phase with the original coupled field in the operating frequency band, thereby effectively canceling part of the mutual coupling energy between antenna units and further improving the port isolation.

[0045] 5. The coordinated design of rectangular slots and parasitic branches effectively blocks and cancels out coupling currents in both low and high frequency bands.

[0046] 6. A parasitic decoupling strip is set up, which generates an induced current when adjacent antenna elements are working. The radiation field of this induced current in space has a similar amplitude and opposite phase to the direct coupling field between antenna elements, thereby significantly suppressing electromagnetic coupling across the entire frequency band and greatly improving the isolation and diversity performance of the four-element MIMO antenna.

[0047] 7. The collaborative design of rectangular slots, parasitic stubs, and parasitic decoupling strips effectively suppresses coupling paths in the two separate frequency bands, significantly reducing inter-element mutual coupling interference in a compact four-element MIMO antenna. This achieves efficient decoupling, excellent port isolation (better than 15dB across the entire operating band and better than 20dB at higher frequencies), and high-density integration within a compact size across both frequency bands. Simultaneously, it fully utilizes the space of the dielectric substrate without increasing the antenna profile height (overall thickness is only 0.5 mm) or adding additional lumped elements. This means that high port isolation across both frequency bands is achieved without introducing additional lumped elements or complex multilayer structures, maintaining high isolation performance across the entire frequency band. Furthermore, it improves antenna radiation efficiency, impedance matching performance, and envelope correlation coefficient (ECC), thereby enhancing diversity gain and channel capacity, avoiding current distribution disturbances, and improving antenna pattern stability.

[0048] 8. Four antenna elements are integrated within a compact size of 51×48×0.5 mm³ (reduced to three-quarters the size of existing technologies), achieving excellent pattern diversity characteristics and low envelope correlation coefficient. It can be widely used in various space-constrained wireless communication terminal devices that require multi-band compatibility, especially IoT gateways supporting dual-band Wi-Fi and 5G Sub-6 GHz multi-mode access, vehicle multimedia communication modules, industrial-grade wireless routers, high-definition video transmission equipment, smart home control centers, portable mobile terminals, and C-band satellite IoT applications that have stringent requirements for antenna miniaturization, multi-band coverage, high port isolation, and spatial integration.

[0049] In a specific embodiment, such as Figure 4 As shown, the overall dimensions of the antenna are 51×48×0.5mm³. Specific dimensional parameters include: the dielectric substrate is FR4 (dielectric constant 4.4, loss tangent 0.02), with a length of 51mm, a width of 48mm, and a thickness of 0.5mm; in the radiating patch, the radius of the first side is 4.4mm, the radius of the second side is 5.8mm, and the center distance between the first and second sides is 1.3mm; in the feed stub, the width is 0.9mm, the length of the first strip is 3mm (the distance from the first strip to the long side of the dielectric substrate is 9.5mm), the second strip is divided into three segments (lengths of 4mm, 3.4mm, and 3.5mm respectively), and the third strip is divided into three segments (lengths of: (3.5mm, 3.4mm, 4mm), the length of the fourth strip is 3mm; the length of the floor is 20mm and the width is 3mm, the length of the rectangular groove is 4mm and the width is 2mm, the length of the parasitic branch is 2mm and the width is 0.2mm; in the parasitic decoupling strip, the length of the rectangular branch is 19.5mm, the width of the rectangular branch is 1mm, and the distance between two rectangular branches is 3mm.

[0050] The antenna was simulated using the electromagnetic full-wave simulation software CST. Its structural parameters, S-parameters, radiation characteristics, and diversity performance were analyzed. The results are as follows: Figures 5 to 13 As shown.

[0051] like Figure 5 As shown, the antenna's return loss S 11 The impedance difference is less than -10dB in both the 2.40-2.50 GHz and 4.56-6.32 GHz frequency ranges, demonstrating that the antenna has excellent ultra-wideband impedance matching characteristics; S 21 and S 31 The curves show that the antenna isolation is better than 15dB across the entire operating frequency band, and better than 20dB at high frequencies.

[0052] like Figure 6 As shown, the antenna gain is stable within the operating frequency band, with a peak gain of 4.1 dBi, indicating that the antenna has good radiation efficiency.

[0053] like Figure 7 As shown, the envelope correlation coefficient (ECC) is below 0.2, which meets the requirement of ECC < 0.5 and is close to the ideal value of 0, proving that the antenna has excellent diversity performance and can effectively combat multipath fading.

[0054] like Figures 8 to 13 As shown, the antenna exhibits circular radiation patterns in both the E and H planes, demonstrating good omnidirectional performance. The antenna's radiation patterns at different frequencies show good consistency, proving its radiation stability within the operating bandwidth.

[0055] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0056] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0057] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended application documents.

Claims

1. A miniaturized MIMO antenna, characterized in that, include: A rectangular dielectric substrate, four radiating components disposed on the upper surface of the dielectric substrate, and four floor components disposed on the lower surface of the dielectric substrate; The four radiating components are axially symmetric about any axis of symmetry of the dielectric substrate; The four radiating components correspond one-to-one with the four floor panels, and the radiating components are positioned above the corresponding floor panels so that the radiating components and the corresponding floor panels form an antenna unit; The radiating component includes a radiating patch and a power supply stub; the radiating patch has a crescent-shaped structure, and the power supply stub has a symmetrical square wave signal shape structure; one end of the power supply stub is connected to the radiating patch, and the other end is connected to the edge of the dielectric substrate to serve as a power supply port.

2. The miniaturized MIMO antenna according to claim 1, wherein, The radiation patch includes: a first side, a second side, and a third side; The first side and the second side are both arc-shaped structures, and the third side is a straight structure; The radius of the first side is smaller than the radius of the second side, one corresponding end of the first side and the second side coincide, and the other corresponding end is connected by the third side.

3. The miniaturized MIMO antenna of claim 2, wherein, The central angles corresponding to the first side and the second side are both greater than 150 degrees, and the opening ends of the adjacent radiating patches face the corners of the dielectric substrate.

4. The miniaturized MIMO antenna according to claim 3, wherein, The power supply branch includes: a first strip, a second strip, a third strip, and a fourth strip; The first strip has a rectangular structure, with one end perpendicularly connected to the edge of the dielectric substrate and the other end connected to the second strip; The second strip has a U-shaped structure, with one end perpendicularly connected to the first strip and the other end connected to the third strip; The third strip has a U-shaped structure, with one end connected to the second strip and the other end perpendicularly connected to the fourth strip; The fourth strip has a rectangular structure, with one end connected to the third strip and the other end connected to the radiating patch; The first strip and the fourth strip are exactly the same in shape and size, the second strip and the third strip are exactly the same in shape and size, and the second strip and the third strip are centrally symmetrical about the connection point.

5. The miniaturized MIMO antenna according to claim 4, characterized in that The axis of symmetry in the length direction of the first strip, the axis of symmetry in the length direction of the fourth strip, the center of the first side, and the center of the second side are collinear.

6. The miniaturized MIMO antenna according to any one of claims 1 to 5, characterized in that The floor is a rectangular structure, with its length direction aligned with the width direction of the dielectric substrate, and a pair of adjacent sides of the floor being collinear with a pair of adjacent sides of the dielectric substrate.

7. The miniaturized MIMO antenna according to claim 6, characterized in that The middle of one long side of the floor is recessed towards the short side of the dielectric substrate to form a rectangular groove; The length direction of the rectangular groove is consistent with the width direction of the dielectric substrate, and the length-to-width ratio of the rectangular groove is 2:

1.

8. The miniaturized MIMO antenna according to claim 7, characterized in that The floor also has parasitic branches; The parasitic branch has a rectangular structure, with one end connected to the short side of the floor and the other end extending towards the axis of symmetry in the length direction of the dielectric substrate, forming a gap between it and the axis of symmetry in the length direction of the dielectric substrate, so that the parasitic branches of adjacent floorboards are spaced apart.

9. A miniaturized MIMO antenna according to any one of claims 1 to 5, characterized in that, Also includes: Parasitic uncoupling bands; The parasitic decoupling strip has a rectangular structure and is located on the lower surface of the dielectric substrate; The length direction of the parasitic decoupling strip is consistent with the length direction of the dielectric substrate, and the parasitic decoupling strip is axially symmetrical about any axis of symmetry of the dielectric substrate.

10. The miniaturized MIMO antenna of claim 9, wherein, The parasitic decoupling strip has a gap in the middle to divide the parasitic decoupling strip into two identical rectangular branches; The ratio of the length of the rectangular branch, the width of the rectangular branch, and the distance between two rectangular branches is 39:2:15.

Images